Numerous medical procedures involve percutaneous administration of fluids into, or removal of fluids from, a patient's body. Percutaneous access devices are typically used in performing these medical procedures and provide access into a patient's body cavity, vessel or organ. Such percutaneous access devices include, among other things, devices for gastrostomy, jejunostomy, angioplasty, and peritoneal dialysis. Often times, it is desirable for such percutaneous access devices to have a portion outside the patient's body which helps retain the device in place and provides a means of attaching medical tubing. As will be explained, there is a need for the external portion to have a low profile, and for the percutaneous access device to have minimal contact with the patient's skin to reduce irritation to the skin and allow ease of access to the skin underlying the device for cleaning. Also, there is a need for a percutaneous access device having suitable differentiation between its multiple tubes or fluid ports.
As an example, and to further describe the background of the invention, one type of commonly used percutaneous access device is the gastrostomy device. For patients having chronic or acute nutritional needs, percutaneous enteral feeding through a stoma, such as a gastrostomy, is often necessary. The gastrostomy is typically formed through use of a percutaneous endoscopic technique and intubated with a gastrostomy tube to effect enteral feeding.
After initial formation and intubation of the gastrostomy, it is often necessary to replace the gastrostomy tube with a device more suitable to long-term feeding needs. It is preferable for these devices to have a low structural profile located closely to the patient's skin outside of the abdominal wall, without discomfort or undue bulging or snagging of clothing. A gastrostomy tube includes a feeding lumen and an inflation lumen. The feeding tube has a proximal end that connects to a nutrient source, and a distal end disposed within the patient. The inflation lumen has one proximal end that connects to an inflation medium source, such as pressurized fluid or air, and another end in communication with an inflatable retention member. The inflatable retention member is located inside the patient's stomach, where it is inflated by connection to an inflation medium source through the inflation tube, for anchoring and retaining the distal end of the gastrostomy tube within the stomach. To retain the device close to the outer abdominal wall of the patient, a retention platform is used, which typically has been a flat disk-shaped member. The disk-shaped member is connected to the tube portion of the device and is positioned flush against the patient's skin. When the device is not in use for enteral feeding, a closure is provided to seal the feeding tube.
An example of one prior art gastrostomy device is found in U.S. Pat. No. 5,125,897. The device disclosed in this patent includes a retention platform which, upon intubation, rests on the abdominal wall of the patient to secure the device. Means are provided to seal the feeding tube when it is not in use. U.S. Pat. No. 4,863,438 shows another gastrostomy device having a type of retention platform utilizing a pair of short flat wings integrally molded on the outer end of the tube, to make the tube self-retaining and flush up against the skin. If skin irritation should occur, the wings can be rotated a part-turn to different areas of the skin. U.S. Pat. No. 4,315,513 shows a gastrostomy device utilizing a retention platform which is a flat disk-shaped member. The surface of the retention platform which faces the skin is provided with a set of raised ridges arranged in spoke-like fashion. The raised ridges maintain the retention platform slightly spaced away from the outer abdominal wall to permit the entry of air between the skin and retention platform.
There are many problems associated with the prior art percutaneous access devices, such as the prior art gastrostomy devices. One such problem with some devices is that, when the device is inserted into the patient for an extended period, the retention platform is in constant contact with the skin where it often causes discomfort to the patient. The retention platforms in most devices are generally flat, and thus a significant portion of the surface area of the platform contacts the skin. As a result, the skin can become irritated due to the lack of air ventilation to the portion of skin next to the retention platform. Although some retention platforms have been designed with orifices to help ventilate the skin underlying the retention platform, such ventilation has been less than desirable, as skin irritation can still occur. In addition, the skin underlying the retention platform cannot be adequately ventilated or cleaned when the retention platform sits closely against the skin of the patient.
Another problem occurs when the percutaneous medical procedure is performed, such as when the feeding process is initiated with a gastrostomy device. Users potentially confuse the inflation tube inlet port for the feeding tube inlet port because they are located in close proximity to one another. As a result, the inflation tube inlet can be erroneously connected with the nutrient source, so that the inflatable retention member is filled with food. In such a case, the inflatable retention member eventually bursts inside the stomach of the patient. The gastrostomy device must then be removed from the patient and a new gastrostomy device inserted. This is expensive, inconvenient and painful to the patient.
Hence, prior to the development of the present invention, a need existed for a percutaneous access device which addresses the problems associated with the prior art devices.